This invention relates to sports shoes adapted to tightly clamp the upper cover by means of a shoe string.
Conventional sports shoes generally known so far adapted to tightly close the forward opening in the upper cover include those types in which a plurality of string passage apertures are perforated at an equi-distance along both side edges of the forward opening for tightening a shoe string through the string passage apertures, or in which ring-like members of a relatively large size, for example, of a D-shaped configuration, are provided on the upper cover instead of the string passage apertures for tightening the shoe string.
However, the former type sports shoes adapted to tie the shoe string by means of the string passage apertures are disadvantageous in that although a sufficient tension of the shoe string obtained by the tightening can be exerted only at the upper end of the forward opening in the upper cover, that is, only at a portion near the tying position of the shoe string an intense tightening effect is available, such a tension by the tightening of the shoe string can not smoothly be transmitted to a portion near the toe of the shoe and accordingly, tightening effect can not be readily obtained throughout the entire portion of the upper cover. This is attributable to the fact that a shoe string inserted through the string passage apertures and engaging their bore edges is hindered from smooth sliding due to the frictional resistance, as well as the fact that a portion of the shoe string near the string passage apertures is forcibly put between the upper cover and a tongue-like inner pad member to further hinder the smooth sliding of the shoe string, thereby making it more difficult to transmit the tightening effect obtained by the tying of the shoe string to the toe portion of the shoe.
Accordingly, there has been a drawback in this type of the sports shoes that the uniform tightening effect by tying the shoe string is difficult to obtain throughout the upper cover and that no well-balanced tightening effect can be attained with ease by prevailing the tension of the shoe string obtained by the tightening of it over the entire portion of the forward opening, although it has a merit that the shoe string once tightened by the tying would not be readily loosened even if a shoe wearer takes exercise with vigorous footwork.
While on the other hand, in the latter type of the sports shoes adapted to tie a string by the ring-like members, since each ring-like member for inserting the shoe string is formed with a large bore, made of highly smooth material with less frictional resistance such as metal or plastic and often shaped in a semi-circular or elliptic configuration, the shoe string engaging the bore edge of the ring-like member is not hindered from smooth sliding. Accordingly, in the sports shoes of the latter type, the tightening force obtained by the tying of the shoe string can be well transmitted from the tying position of the shoe string to the vicinity of the toe to exert an effective clamping effect all over the upper cover. On the contrary, shocks due to the wearer's vigorous movement are liable to extend on the tying position of the shoe string, which are directly transmitted throughout the upper cover to rapidly cancel the tightening force by the tying of the string.
This invention has been made in view of the foregoing defects in sports shoes of the type adapted to tie a shoe string by string passage apertures, as well as by another type provided with highly smooth ring-like members.
It is an object of this invention to provide sports shoes, wherein the tightening force obtained by the clamping of a shoe string can be transmitted substantially over the entire portion of the upper cover, which is not lost rapidly, but can provide a long lasting satisfactory tightening force.